Question

The fatigue life of a part can be improved by
1. Electroplating
2. Polishing
3. Coating
4. Shot peening

Answer 1

Correct Answer - Option 4 : Shot peening

Explanation:

Shot peening 

• It is a cold work process used to finish metal parts to prevent fatigue and stress corrosion failures and prolong product life for the part.
• In shot peening, a small spherical shot bombards the surface of the part to be finished.
• The shot acts like a peen hammer, dimpling the surface and causing compression stresses under the dimple.
• The surface compression stress strengthens the metal, ensuring that the finished part will resist fatigue failures, corrosion fatigue and cracking, and galling and erosion from cavitation.